Chemical Assignment of Structural Isomers of Sulfur-Containing Metabolites in Garlic by Liquid Chromatography-Fourier Transform Ion Cyclotron Resonance-Mass Spectrometry.
J Nutr
; 146(2): 397S-402S, 2016 Feb.
Article
em En
| MEDLINE
| ID: mdl-26764333
ABSTRACT
BACKGROUND:
The chemical assignment of metabolites is crucial to understanding the relation between food composition and biological activity.OBJECTIVE:
This study was designed to detect and chemically assign sulfur-containing metabolites by using LC-Fourier transform ion cyclotron resonance-mass spectrometry (FTICR-MS) in Allium plants.METHODS:
Ultrahigh resolution (>250,000 full width at half-maximum) and mass accuracy (<1 mDa) by FTICR-MS allowed us to distinguish ions containing sulfur isotopes ((32)S and (34)S).RESULTS:
Putative 69 S-containing monoisotopic ions (S-ions) were extracted from the metabolome data of onion (Allium cepa), green onion (Allium fistulosum), and garlic (Allium sativum) on the basis of theoretical mass differences between (32)S-ions and their (34)S-substituted counterparts and on the natural abundance of (34)S. Eight S-ions were chemically assigned by using the reference data according to the guidelines of the Metabolomics Standards Initiative. Three ions detected in garlic were assigned as derived from the isomers γ-glutamyl-S-1-propenylcysteine and γ-glutamyl-S-2-propenylcysteine and as S-2-propenylmercaptoglutathione on the basis of differences in key product ions identified in reference tandem MS spectra.CONCLUSION:
The ability to discriminate between such geometric isomers will be extremely useful for the chemical assignment of unknown metabolites in MS-based metabolomics.Palavras-chave
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Base de dados:
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Assunto principal:
Enxofre
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Espectroscopia de Infravermelho com Transformada de Fourier
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Cebolas
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Cisteína
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Alho
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Glutationa
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Íons
Idioma:
En
Ano de publicação:
2016
Tipo de documento:
Article